A senior Liberal says the prime minister does not need cabinet approval for the creation of a security 'super department' as experts question the need for such a move.
Sky News has revealed Prime Minister Malcolm Turnbull is preparing to announce plans for a British Home Office-style portfolio that will encompass ASIO, the Australian Federal Police, Immigration and Border Force.
The move is expected to be signed off today by cabinet, though Defence Industry Minister Christopher Pyne says its approval is not needed.
There is also no formal submission for the creation of the department before cabinet ministers.
'If a new structure is established it will be because the prime minister has made the assessment that is the best thing for Australia's security,' Mr Pyne told Sky News.
Immigration Minister Peter Dutton is likely to be given the job of overseeing the super portfolio, but experts have questioned the motives.
The ANU's Professor Michael Wesley told Sky News it was not clear what part of Australia's security apparatus needed to be fixed.
'We have a system that works extremely well and playing politics with Australians' lives and safety, potentially, is an extremely bad move in my view,'
'If there is a need it's a well kept secret,' national security expert Professor Greg Barton told Sky News.
'No one who works in this area apart from Peter Dutton and some other ministers who, for political faction reasons are keen on the idea, have come forward with a reason (for creating the department).'
Mr Pyne said it was 'ludicrous' to suggest any departmental change was politically motivated.
He said there was no consideration being made to anything other than national security.
Labor has called on the government to provide its advice on why a new national security super-department is needed.
Opposition frontbencher Katy Gallagher says the opposition is prepared to work with the government in the national interest.
But she was staggered to see critical changes to national security 'carelessly' leaked to the media ahead of a decision being made.
'Australians would be very concerned if a new national security super department is being created just to keep Peter Dutton happy, especially when it's so vehemently opposed by so many of his colleagues,' she says.
'We expect any changes to be based on the recommendations of our security agencies - we want to hear what the experts have to say.'
Cabinet has previously rejected the idea of a Home Office or US-style Department of Homeland Security based on advice from experts.
A 2015 review of Australia's counter-terrorism machinery found a super agency 'would likely be less, not more, responsive as large agencies tend to be less agile, less adaptable and more inward looking than smaller departments'.
The government has received the report of another review, conducted by former senior public servants Michael L'Estrange and Stephen Merchant, but is yet to release its findings.